Nikon D40x Manuel D’Utilisation

The metering method determines how the camera sets exposure.  The following options
are available when the mode dial is rotated to P, S, A, or M (matrix metering is used in other
modes):

Metering is available with CPU lenses only.  In matrix metering, exposure is set using a 420-pixel RGB
sensor.  Use a type G or D lens for results that include range information (3D color matrix metering II; 
97).  With other CPU lenses, 3D range information is not included (color matrix metering II).

CPU lenses can be identified by the presence of CPU contacts, type G and D lenses by a letter on the
lens barrel.  Type G lenses are not equipped with a lens aperture ring.

CPU lens

Type G lens

Type D lens

Metering can also be selected from the Custom Settings menu.

Matrix

Recommended in most situations.  Camera meters a wide area of the frame
and instantly sets exposure according to distribution of brightness, color, dis-
tance, and composition for natural results.

Center-weighted

Camera meters entire frame but assigns greatest weight to center area.  Clas-
sic meter for portraits.

Spot

Camera meters exposure in active focus area only (if Closest subject is
selected for AF-area mode (  24), camera will meter center focus area).
Ensures that subject will be correctly exposed, even when background is
much brighter or darker.